Drawing instrument



A. G. CAMERON. DRAWING INSTRUMENT. APPLICATION FILED JULY I9.1920.

Patented Dec. l2, 1 .922.

stars ALEXANDER G'. CAIVIEBON, 0F WINNIPEG, MANITOBA, CANADA.

DRAWING INSTRUMENT. 1

Application filed July 19,

To all whom it may concern:

Be it known that I, ALEXANDER G. CAIVP neon, of the city of Winnipeg, in the Province of Manitoba, Canada, have invented certain new and useful Improvements in Drawing Instruments, of which the following is the specification.

The invention relates to improvements in drawing instruments and an object of the invention is to provide a drawing instrument which can be used by draughtsinen, mechanics or such persons for quickly and accurately drawing regular or irregular, straight or curved lines or figures and which is. arranged so that it can be quickly and positively set and easily manipulated.

A further object is to provide an instru ment whereby one can readily reproduce in a drawing an irregular curve, the instrument being first applied to the curved surface, then fitted and set and afterwards utilized to draw the curve and provide-the required reproduction. U

A further object is to provideua' light, compact, easilyassembled and simplyconstructed instrument which can be readily manufactured and sold at comparatively low cost.

A further-object is to provide a drawing instrument which can be readily enlarged or decreased in size to suit requirements.

lVith the above more important objects in View the invention consists essentially'in.

the arrangement and construction of parts hereinafter more particularly describedand later pointed out in the appended claims, reference being had to the accompanying drawing in which l Fig. 1 is a plan view of the instrument. Fig. 2 is an edge view thereof. Fig. 3 is an enlarged detailed horizontal sectional view centrally through the joint formed between adjacent sections. l Fig. 4: is an enlarged detailed vertical sectional view through the joint formed between the adjacent sections; r

Fig. 5 is an enlarged detailed vertical sec tional View through the block carried by the central section, the adjusting screwand associated parts being shown in side elevation. 1 .7

Fig. 6 is an enlargeddetailed vertical sectional view at 6-6 Fig. 1. v

Fig. 7 is a perspective view of the end arm. 1

1920. Serial No. 397,540.

Fig. 8 is a perspective view of the set screw.

Fig. 9 is a plan view of the locking clamp.

Fig. 10 is a sectional view at 10-10 Fig. 9.

In the drawing like characters of refer ence indicate corresponding parts in the sev eral figures. at

The present instrument is shown as formed fromthree similar adjustable sections 1, 2 and 3, an end arm 4 and a flexible ruling bar 5. I wish here, however, to state that whilst three sections are shown any number of sections could be connected together in an instrument. this depending entirely on the requirements.

The central section 2 is formed from an upper and lower pair of channel bars 6 and 7 of a predetermined length and having the flanges of the channel bars cut away at the ends to provide extending end bearings 8 and 9. A block 10 is inserted centrally be tween, the channel. bars and is securelyv riveted to them as indicated atll.

j The end sections 1 and 3 are identically constructed, these also being formed from channel bars of predetermined length and also having the flanges cut away at the ends. The outer ends of the channel bars of the sections 1 and 3 form bearings 12 whilst the inner ends are cut away in a semi-circular manner as indicated at 18 to fit the semi circular ends of the section 2. c

In all the sections the flanges of the channel bars extend towards each other but are spaced apart to provide side guides indicated at l twhich admit the adjusting screws hereinafter referred to. r

The innerends of thesections 1 and 3 are pivotally secured to the ends. of the section 2 by nieansof pivot .pins 15 and 16. The joint is made by securing as by riveting at 1'7 spaced extending end strips 18 to the inner ends of the sections 1 and 8 and having the pins 15 and 16 passing pivotally through the extendingends of the strips 18. Spacing str1ps 19 are inserted between the spaced ends of the strips 18, the said strips 19 be ing really part of the central section and being pivotally mounted on the pivot pins 15 and 16.

This arrangement provides a particularly strong pivot joint between the sections. The outer ends of thesections 1 and 3 are plugged between the bearings 12 by a filling plug 20 riveted as indicated at 21 to the section. The

blocks are supplied with an exposed cross either of the sections 1 and 3 the end-arm which presents a straight drawing edge it. due end of the end arm is adapted to enter the slot 22 hereinbefore mentioned and it fitted with a pivot opening 25 and an end slot 26 forming an" entrance to the opening 25, the said slot being narrower than the diameter oi the opening 25 and of a width such that it will just nicely span the flat sides 24 Of the screw.

According to this arrangement it will be apparent that the end arm 4 can be attached to either 01": the sections 1 or 3 by passing the flat part of the screw through the slot 26 and into the opening 25. Afterwards one can swing the arm as desired, the screw acting as thepivot point and in this operation it is desirable to press in on the outerend of the arm to prevent the flat part of the screw from escaping out of the slot 26.

The central section ,2 of the instrument is fitted with an adjusting screw or spindle 2? which passes slidably throughthe block 10 and is fitted at opposite sides cit-the section with nuts- 28 and 29.- The sections 1 and 3 of the instrument are also each provided with a pair ofadjusting screws or spindles 30 and 31 which pass through the slots; 14,

' being slidable therein and they are fitted each with a pair of jam nuts 32 and 33 at opposite sides ofthe sections. Obviously by manipulating the jam nuts 28 and 29 the central suindle 27 can be adjusted inor out whilst by manipulating the nuts 32 and 33 the spindles 30 and 31' can not only be adjusted in and out but can also be adjusted endwise in respect to the sections 1 and 3; The flexible ruling bar -5 is connected pivotally as indicated at '34 to the inner endsof the adjusting screws or spindles.

In order" to permit one to positively hold the joints between the sections locked I will provide as part oil the equipment of the instrument a number of lockin'g'clamps which are best shown in Figures 9 and 10, the said clamps 35 being of-a channel bar cross section and having the ends turned at a fixed angle;

With these clamps supplied one can place selected clamps over the joints b'etweenthe sections and the flanges 01. the clamps engaging with the flanges ot the bars of the sections will positively hold the sections lockedagainst turning. v j

From the above description it will be obvious that this instrument can. be used for drawi 0 either straight lineflgurcs, regular or irregular, or curved lines regular or irregular, the straight line figures being This set screw perbar 5.

In order to better understand the possibilities of this instrument I will explain how it can be used in a variety of ways.

In order to draw a straight line one simply releases the jam: nuts 32 and 33 to allow the sections to swing until they are aligned and the straight line'can then be drawn either at the inner or outer edges of the sections To draw, say a regular hexagon, one would adjust the jamnuts to allow the end sections 1 and 3 to take a position at an angle ofsixty degrees to thesection 2. One half of the hexagon can then be drawn and then by turnin overthe rule the other half can be drawn. Various other regular fig-- ures can obviously be drawn by properly setting-the sections and moving the said rule to complete the regular figure.

/Vhere one desires to draw a curved surface he can do-thisloy adjusting the screws 27, 30 and 31 to adjust the flexible ruling bar and then set-the jam nuts to hold it in a fixed position.

The flexible ruling bar arrangement is particularly useful where it isdesired to reproduce the curvature of a fixed body; for making: patterns and such like As an ex ample, supposing one wished to reproduce the curvature of the side'of' a boat, the-back of an automobile on such like he would simply adjust the screws "27 30 r and 31 and set in a multiplicity of waystoraccommo date the work in'a-hand.

The bar l can be attached or detached whendesired andiis readi'lyafitting to the instrumentv rather than an essential part of it. I

What I claim as my invention is:

1. In combination, a plurality of pivotally connected end and intermediate ruling sections, a flexible resilient ruling bar, acon nection between the ruling bar and an intermediate secti0n,:.said connection permitting of the adjustment of the flexiblebar towards and away from the said intermediate section and a'dj ustab'lef connections connecting the flexible bar to the'end-sections, said adjust able connections permitting'of the adjustment of the flexible bar towards and away from the said latter sections and the shifting endwise of the connections in respect to the said latter sections.

2. In combination, a central ruling section, end ruling sections pivotally attached to the ends of the central section, an adjusting screw passing through the central section, means for locking the screw in adjusted relation to the central section, a plurality of adjusting screws passing through the end sections and free to move towards and away "from the ends of the said end sections,rneans for locking the said latter screws in any adjusted position in respect-to the end sections and a flexible resilient ruling bar pivotally attached to the inner ends of the various screws.

3. In combination, a plurality of similar pivotally connected ruling sections comprising a central and end sections and with the end sections presenting lengthwise extending slots, an adjusting screw passing through the central section centrally and adjustable in a direction at right angles to the said central section, a plurality of adjusting screws passing through the slots in the end sections and movable endwise within the slots, means for adjusting the said latter slidably through the block, jam nuts on the i screw at opposite sides of the central section, a plurality of adjusting screws passing through the slots of the end sections and movable endwise within the slots, a pair of jam nuts mounted on each of the latter screws and engageable with the opposite sides of the end sections and a flexible resilient ruling bar connected pivotally to the inner ends of all the screws.

Signed at Winnipeg, Man. this 24 day of F June 1920.

ALEXANDER G. CAMERON.

In the presence 0f:- G. S. ROXBAUGH, K. B. WAKEFIELD. 

